As recreational marijuana legalization (RML) takes place in more areas around the country, it is critical to examine whether rates of marijuana use increase among college students in RML states compared to non-RML states.  As states liberalize laws about marijuana use, colleges and universities affected by these changes can use research from earlier RML states to inform program and policy development prospectively.

The current study used data from the National College Health Assessment (NCHA) that randomly samples students from participating colleges each year.  Data analyzed were from 2008 to 2016 and included the two 4-year colleges in Oregon that participated in NCHA before and after the 2015 legalization of marijuana there (n = 7,412 undergraduates).  Comparison data included 247,340 undergraduates from 123 colleges in non-RML states. Measures assessed self-reported use of marijuana, tobacco, alcohol, and other drugs in the last 30 days.

Results found that Oregon students’ rates of marijuana use increased compared to their counterparts in non-RML states.  The increase appears to be due to sporadic marijuana use and not heavy use (10 or more days in the past month).  Interestingly, a concurrent decrease in tobacco use rates was observed in Oregon students after marijuana legalization.  No changes were observed in rates of alcohol or other drug use.

This was a correlational study limited to two institutions in an RML state.  Future studies could include more diverse institution and control for campus substance use policies.

Take Away: College students increase their use of marijuana and decrease their use of tobacco after legalization of recreational marijuana in Oregon.  Alcohol and other drug use rates are not affected.

Kerr, D.C.R., Bae, H. & Koval, A.L. (2018). Oregon recreational marijuana Legalization: Changes in undergraduates’ marijuana use rates from 2008 to 2016. Psychology of Addictive Behaviors, 32(6), 670-678. doi.org/10.1037/ADB0000385